197 research outputs found

    Energy Dissipation Burst on the Traffic Congestion

    Get PDF
    We introduce an energy dissipation model for traffic flow based on the optimal velocity model (OV model). In this model, vehicles are defined as moving under the rule of the OV model, and energy dissipation rate is defined as the product of the velocity of a vehicle and resistant force which works to it.Comment: 15 pages, 19 Postscript figures. Reason for replacing: This is the submitted for

    Atomistic basis of force generation, translocation, and coordination in a viral genome packaging motor

    Get PDF
    Double-stranded DNA viruses package their genomes into pre-assembled capsids using virally-encoded ASCE ATPase ring motors. We present the first atomic-resolution crystal structure of a multimeric ring form of a viral dsDNA packaging motor, the ATPase of the asccphi28 phage, and characterize its atomic-level dynamics via long timescale molecular dynamics simulations. Based on these results, and previous single-molecule data and cryo-EM reconstruction of the homologous phi29 motor, we propose an overall packaging model that is driven by helical-to-planar transitions of the ring motor. These transitions are coordinated by inter-subunit interactions that regulate catalytic and force-generating events. Stepwise ATP binding to individual subunits increase their affinity for the helical DNA phosphate backbone, resulting in distortion away from the planar ring towards a helical configuration, inducing mechanical strain. Subsequent sequential hydrolysis events alleviate the accumulated mechanical strain, allowing a stepwise return of the motor to the planar conformation, translocating DNA in the process. This type of helical-to-planar mechanism could serve as a general framework for ring ATPases

    Quality of Work Life and Mental Health in Primary Care Physicians

    Get PDF
    AbstractThe aim of this study was to find the relationship between the perception of Quality of Work Life (QWL) and the mental health of primary care physicians of a public health institution in Guadalajara, Mexico. The study was analytical and was carried out with a universe of 818 doctors from 92 health units and the probability sample of 154 people. In all of them, CVT-GOHISALO and Goldberg GHQ-28 questionnaires were applied in order to measure their perception of QWL and the risk of mental illness respectively. Both instruments were selected because of their high reliability. We measured the satisfaction of the people interviewed for each one of the seven dimensions of CVT-GOHISALO and related to the points assigned to GHQ-28 case or not to consider the case of mental illness. The percentages of dissatisfaction with the QWL were greater than 12% in all dimensions of the instrument, being the highest value of 20.5% dissatisfaction for the job satisfaction dimension. In the classification of the case or not according to the GHQ-28, 22% were considered cases and 78% non-cases. We sought correspondence of satisfaction with the QWL by dimensions and non-case of Goldberg's, as well as dissatisfaction with the QWL and Goldberg's case, finding a clear link between being satisfied and having mental health. All dimensions have a correspondence that goes from 79.7% to 82.3% between satisfaction and non-case, being in all the statistical significance value less than 0.05 For primary care physicians in the studied institution, there is a clear relationship between being satisfied with the QWL and present less risk of mental illness. It is alarming that the medical staff presents high rates of dissatisfaction with the QWL and risk of mental illness. It is necessary to provide preventive programs among health care workers in order to improve their QWL and mental health

    Using temperature as observable of the frequency response of RF CMOS amplifiers

    Get PDF
    The power dissipated by the devices of an integrated circuit can be considered a signature of the circuit's performance. Without disturbing the circuit operation, this power consumption can be monitored by temperature measurements on the silicon surface. In this paper, the frequency response of a RF LNA is observed by measuring spectral components of the sensed temperature. Results prove that temperature can be used to debug and observe figures of merit of analog blocks in a RFIC. Experimental measurements have been done in a 0.25 mum CMOS process. Laser probing techniques have been used as temperature sensors; specifically, a thermoreflectometer and a Michaelson interferometer.Peer ReviewedPostprint (author's final draft

    Resection of the liver for colorectal carcinoma metastases - A multi-institutional study of long-term survivors

    Get PDF
    In this review of a collected series of patients undergoing hepatic resection for colorectal metastases, 100 patients were found to have survived greater than five years from the time of resection. Of these 100 long-term survivors, 71 remain disease-free through the last follow-up, 19 recurred prior to five years, and ten recurred after five years. Patient characteristics that may have contributed to survival were examined. Procedures performed included five trisegmentectomies, 32 lobectomies, 16 left lateral segmentectomies, and 45 wedge resections. The margin of resection was recorded in 27 patients, one of whom had a positive margin, nine of whom had a less than or equal to 1-cm margin, and 17 of whom had a greater than 1-cm margin. Eighty-one patients had a solitary metastasis to the liver, 11 patients had two metastases, one patient had three metastases, and four patients had four metastases. Thirty patients had Stage C primary carcinoma, 40 had Stage B primary carcinoma, and one had Stage A primarycarcinoma. The disease-free interval from the time of colon resection to the time of liver resection was less than one year in 65 patients, and greater than one year in 34 patients. Three patients had bilobar metastases. Four of the patients had extrahepatic disease resected simultaneously with the liver resection. Though several contraindications to hepatic resection have been proposed in the past, five-year survival has been found in patients with extrahepatic disease resected simultaneously, patients with bilobar metastases, patients with multiple metastases, and patients with positive margins. Five-year disease-free survivors are also present in each of these subsets. It is concluded that five-year survival is possible in the presence of reported contraindications to resection, and therefore that the decision to resect the liver must be individualized. © 1988 American Society of Colon and Rectal Surgeons
    corecore